prometheus.operator.*, simplify cluster update logic. (#4852)

* prometheus.operator.* simplify logic for cluster updates

* remove uneeded extra variable

component/prometheus/operator/common/component.go

@@ -51,7 +51,6 @@ func (c *Component) Run(ctx context.Context) error {
 		}
 	}()
 
-	var runningConfig *operator.Arguments
 	c.reportHealth(nil)
 	errChan := make(chan error, 1)
 	for {
@@ -64,28 +63,19 @@ func (c *Component) Run(ctx context.Context) error {
 		case err := <-errChan:
 			c.reportHealth(err)
 		case <-c.onUpdate:
-
 			c.mut.Lock()
-			nextConfig := c.config
-			// only restart crd manager if our config has changed.
-			// NOT on cluster changes.
-			if !nextConfig.Equals(runningConfig) {
-				runningConfig = nextConfig
-				manager := newCrdManager(c.opts, c.opts.Logger, nextConfig, c.kind)
-				c.manager = manager
-				if cancel != nil {
-					cancel()
-				}
-				innerCtx, cancel = context.WithCancel(ctx)
-				go func() {
-					if err := manager.Run(innerCtx); err != nil {
-						level.Error(c.opts.Logger).Log("msg", "error running crd manager", "err", err)
-						errChan <- err
-					}
-				}()
-			} else {
-				c.manager.ClusteringUpdated()
+			manager := newCrdManager(c.opts, c.opts.Logger, c.config, c.kind)
+			c.manager = manager
+			if cancel != nil {
+				cancel()
 			}
+			innerCtx, cancel = context.WithCancel(ctx)
+			go func() {
+				if err := manager.Run(innerCtx); err != nil {
+					level.Error(c.opts.Logger).Log("msg", "error running crd manager", "err", err)
+					errChan <- err
+				}
+			}()
 			c.mut.Unlock()
 		}
 	}
@@ -115,11 +105,7 @@ func (c *Component) NotifyClusterChange() {
 		return // no-op
 	}
 
-	// Schedule a reload so targets get redistributed.
-	select {
-	case c.onUpdate <- struct{}{}:
-	default:
-	}
+	c.manager.ClusteringUpdated()
 }
 
 // DebugInfo returns debug information for this component.

component/prometheus/operator/types.go

@@ -1,7 +1,6 @@
 package operator
 
 import (
-	"reflect"
 	"time"
 
 	"github.com/grafana/agent/component/common/config"
@@ -30,10 +29,6 @@ type Arguments struct {
 	RelabelConfigs []*flow_relabel.Config `river:"rule,block,optional"`
 }
 
-func (a *Arguments) Equals(b *Arguments) bool {
-	return reflect.DeepEqual(a, b)
-}
-
 // Clustering holds values that configure clustering-specific behavior.
 type Clustering struct {
 	// TODO(@tpaschalis) Move this block to a shared place for all components using clustering.

component/prometheus/operator/types_test.go

@@ -27,20 +27,3 @@ func TestRiverUnmarshal(t *testing.T) {
 	err := river.Unmarshal([]byte(exampleRiverConfig), &args)
 	require.NoError(t, err)
 }
-
-func TestEqual(t *testing.T) {
-	a := Arguments{
-		Namespaces: []string{"my-app"},
-		Clustering: Clustering{Enabled: true},
-	}
-	b := Arguments{
-		Namespaces: []string{"my-app"},
-		Clustering: Clustering{Enabled: true},
-	}
-	c := Arguments{
-		Namespaces: []string{"my-app", "other-app"},
-		Clustering: Clustering{Enabled: false},
-	}
-	require.True(t, a.Equals(&b))
-	require.False(t, a.Equals(&c))
-}